An all inorganic Li/SO.sub.2 rechargeable cell generally includes a lithium anode, a porous carbon cathode and a stable highly conductive liquid electrolyte complex LiAlCl.sub.4 --xSO.sub.2. This complex is rapidly formed when the commonly used LiAlCl.sub.4 electrolyte salt reacts with SO.sub.2 gas or SO.sub.2 liquid. Although the initially formed liquid complex has the formula LiAlCl.sub.4 --3SO.sub.2, additional lowered LiAlCl.sub.4 salt concentration can be achieved at will by diluting the above electrolyte with additional SO.sub.2. Thus, electrolyte with formulas LiAlCl--xSO.sub.2 where x is at least 3 can be prepared. The starting electrolyte LiAlCl.sub.4 --3SO.sub.2 has a very high specific conductivity of 0.1 S/cm. The fact that this is the highest known conductivity for any ambient temperature non aqueous electrolyte makes this general class of electrolytes extremely valuable.
One difficulty with the use of this electrolyte is however, that during cell discharge, the insoluble reduction product is deposited in the porous carbon cathode. Simultaneously, some of the LiAlCl.sub.4 electrolyte salt is also precipitated in the porous carbon cathode. The coprecipitation of electrolyte salt is partially responsible for the severely reduced capacity currently plaguing this system.